1. Field of the Invention
The present invention relates to a light communication apparatus, and particularly to a light communication apparatus that includes a plurality of light communication apparatus units and is arranged so that all the light communication apparatus units are connected at the same time to optical fibers numbering the same as the communication apparatus units.
2. Description of the Related Art
A light communication apparatus unit in which a photo-connector receptacle, an optical element and a peripheral circuit of the optical element are integrated with one another is used broadly in the field of light communication. FIGS. 4(a) and 4(b) show a conventional light communication apparatus unit in a perspective view and a partly sectional view respectively. The light communication apparatus unit 10 shown in FIGS. 4(a) and 4(b) includes photo-connector receptacle 41 attached on a side surface of housing 11, optical element 43 mounted on photo-connector receptacle 41, and peripheral circuit 44 of optical element 43 housed within the housing 11 and electrically connected with optical element 43. The photo-connector receptacle 41 is attached so as to penetrate housing 11. Optical element 43 is supported by a holder 45 integrally formed with optical member 47, a lens or the like, and mounted on an end portion of photo-connector receptacle 41 inside housing 11. Sleeve 46 is provided interior the section of photo-connector receptacle 41 exposed outside housing 11 so that a photo-connector plug attached to an optical fiber can be connected with high precision. Further, terminal 42, for electrically connecting light communication apparatus unit 10 with another electric circuit, are provided so as to be exposed outside the housing 11.
FIG. 5 shows a partly sectional plan view of a light communication apparatus including two communication apparatus units of the type described above. The light communication apparatus in FIG. 5 is mainly constituted by receptacle body 22 and two light communication apparatus units 10. Photo-connector receptacles 41 of respective light communication apparatus units 10 in combination with receptacle body 22 constitute two-core photo- connector receptacle 20. A two-core photo-connector plug can be connected to two-core photo-connector receptacle 20 so that optical fibers can be on and off, respectively, in the two light communication apparatus units 10 at the same time. Bolt holes 9 are provided at four places in the receptacle body 22 so that the receptacle body 22 can be fixed to a substrate or the like.
FIGS. 6(a) to 6(c) show the steps of assembling the light communication apparatus of FIG. 5 on a substrate. First, as shown in FIG. 6(a), jig 23 is inserted from the top end of receptacle body 22 and the two light communication apparatus units 10 from the rear end. The respective positions of the light communication apparatus units 10 are determined relative to receptacle body 22. Jig 23 has a shape substantially the same as that of the two-core photo-connector plug connected to the two-core photo-connector receptacle 20 shown in FIG. 5. By placement of jig 23, the positions of the two light communication apparatus units 10 are determined lo so as to comprise a two-core connector receptacle together with receptacle body 22.
Next, as shown in FIG. 6(b), while jig 23 and light communication apparatus units 10 are kept stationary, terminal 12 is soldered in a predetermined position on substrate 25. Finally, as shown in FIG. 6(c), the receptacle body 22 is fixed by bolts 26 and nuts 27, thereby completing a light communication apparatus.
When the above-mentioned conventional light communication apparatus is assembled by the above steps, the positions of light communication apparatus units 10 are determined by use of jig 23, so that errors .DELTA.x, .DELTA.y, .DELTA.z and .DELTA..theta. in the directions indicated in FIG. 7 are restrained within allowable limits.
In such a conventional light communication apparatus, it has been inevitable to determine the positions of light communication apparatus units using a jig at the time of assembly. That is, the positions of light transmitters and receivers have been determined individually by an adjustment jig during assembly process, so as to restrain the positions within a desired accuracy which is necessary for a two-core connector receptacle. Therefore, mass production of the light communication apparatus has been impossible due to the necessity of excess time.
Moreover, in conventional light communication apparatus, housings of respective light communication apparatus units have been made of metal independently, thereby greatly inflating the cost of these portions.